以还原氧化石墨烯和纳米二氧化锆为DNA探针固定平台电化学测定转基因玉米中特定基因序列

草胺膦乙酰转移酶基因(PAT)是一种转基因植物的外源DNA片段。 本文以还原氧化石墨烯和纳米二氧化锆(nanoZrO₂)的复合物作为固定DNA探针的平台,建立了一种灵敏地检测PAT基因的方法。 首先,氧化石墨烯直接在电极表面进行电化学还原,然后将一层nanoZrO₂涂覆于其表面,利用DNA中的磷酸基团与nanoZrO₂中氧的亲和作用固定DNA探针。 通过微分脉冲伏安法检测DNA探针与PAT基因片段的杂交,构建了用于检测PAT基因片段的电化学生物传感器。 该传感器具有稳定性好,重复性好的特点,可灵敏地检测转基因玉米中的PAT基因,检测限达2.0×10^-15 mol/L。

Electrochemical Determination of the Specific Genetic Sequence in Transgenic Maize Using Reduced Graphene Oxide and Nano Zirconia Composites as a Platform for Immobilizing DNA

The phosphinothricin acetyltransferase(PAT) gene is a kind of exogenous DNA segments indicating genetically modified plants. In this research, a sensitive method for determination of the PAT gene in transgenic maize has been developed using reduced graphene oxide and nano zirconia(nanoZrO₂) composites as a platform for immobilizing DNA probes. First, the graphene oxide was direct electrochemically reduced on a glassy carbon electrode(GCE); then, a layer of nanoZrO₂ was covered on the modified electrode. Last, the DNA probes were immobilized via the affinity between phosphate groups in the DNA probes and the oxygen in nanoZrO₂. The hybridization of the DNA probes with the PAT gene segments was monitored by differential pulse voltammetry(DPV). The sensor was stable, reproducible and sensitive to effectively discriminate the PAT gene in transgenic maize. The detection limit was 2.0×10^-15 mol/L.